Late-onset multiple sclerosis in Iran: A report on demographic and disease characteristics

Abstract

Background: Today, it is estimated that around 5 of multiple sclerosis (MS) patients are in the late-onset category (age at disease onset >= 50). Diagnosis and treatment in this group could be challenging. Here, we report the latest update on the characteristics of Iranian patients with late-onset MS (LOMS). Methods: This cross-sectional study used the information provided by the nationwide MS registry of Iran (NMSRI). The registrars from 14 provinces entered data of patients with a confirmed diagnosis of MS by neurologists. Patients with disease onset at or later than 50 years of age were considered LOMS. Results: Of 20,036 records, the late-onset category included 321 patients (1.6). The age-standardized LOMS prevalence was around 75 per 100,000 people. 215 patients (67) were female. Median Expanded Disability Status Scale (EDSS) was 3 (interquartile range: 1.5-5). The majority of the cases (56) suffered from relapsingremitting (RR) course while 20 were diagnosed with primary progressive (PP) MS. Significantly higher proportion of male sex, PPMS, and higher EDSS were seen in the late-onset group compared with early-onset and adult-onset cases (p-value < 0.05). Seventy-five (23) patients did not receive any disease-modifying treatment. Discussion: The more prominent degenerative pathology of LOMS may be the underlying mechanism of the observed differences in comparison to non-LOMS.Conclusion: There are substantial differences and knowledge gaps regarding LOMS which could be the subject of further research.